generator: fix python 3.12 warning

Citing from Python 3.12 release:
"A backslash-character pair that is not a valid escape sequence now generates
 a SyntaxWarning (...) In a future Python version, SyntaxError will eventually
 be raised, instead of SyntaxWarning."

 https://docs.python.org/dev/whatsnew/3.12.html#other-language-changes

Author: garfvl

generator/generate.py

@@ -501,7 +501,7 @@ def parse_param(cls, param_raw):
             assert('const' not in param_raw)
 
             # normalize spaces
-            param_raw = re.sub('\s+', ' ', param_raw)
+            param_raw = re.sub(r'\s+', ' ', param_raw)
 
             split_value = param_raw.split(' ')
             if len(split_value) > 1: